src/script/script.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2017 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #include <script/script.h>
   7
   8 #include <tinyformat.h>
   9 #include <utilstrencodings.h>
  10
  11 const char* GetOpName(opcodetype opcode)
  12 {
  13     switch (opcode)
  14     {
  15     // push value
  16     case OP_0                      : return "0";
  17     case OP_PUSHDATA1              : return "OP_PUSHDATA1";
  18     case OP_PUSHDATA2              : return "OP_PUSHDATA2";
  19     case OP_PUSHDATA4              : return "OP_PUSHDATA4";
  20     case OP_1NEGATE                : return "-1";
  21     case OP_RESERVED               : return "OP_RESERVED";
  22     case OP_1                      : return "1";
  23     case OP_2                      : return "2";
  24     case OP_3                      : return "3";
  25     case OP_4                      : return "4";
  26     case OP_5                      : return "5";
  27     case OP_6                      : return "6";
  28     case OP_7                      : return "7";
  29     case OP_8                      : return "8";
  30     case OP_9                      : return "9";
  31     case OP_10                     : return "10";
  32     case OP_11                     : return "11";
  33     case OP_12                     : return "12";
  34     case OP_13                     : return "13";
  35     case OP_14                     : return "14";
  36     case OP_15                     : return "15";
  37     case OP_16                     : return "16";
  38
  39     // control
  40     case OP_NOP                    : return "OP_NOP";
  41     case OP_VER                    : return "OP_VER";
  42     case OP_IF                     : return "OP_IF";
  43     case OP_NOTIF                  : return "OP_NOTIF";
  44     case OP_VERIF                  : return "OP_VERIF";
  45     case OP_VERNOTIF               : return "OP_VERNOTIF";
  46     case OP_ELSE                   : return "OP_ELSE";
  47     case OP_ENDIF                  : return "OP_ENDIF";
  48     case OP_VERIFY                 : return "OP_VERIFY";
  49     case OP_RETURN                 : return "OP_RETURN";
  50
  51     // stack ops
  52     case OP_TOALTSTACK             : return "OP_TOALTSTACK";
  53     case OP_FROMALTSTACK           : return "OP_FROMALTSTACK";
  54     case OP_2DROP                  : return "OP_2DROP";
  55     case OP_2DUP                   : return "OP_2DUP";
  56     case OP_3DUP                   : return "OP_3DUP";
  57     case OP_2OVER                  : return "OP_2OVER";
  58     case OP_2ROT                   : return "OP_2ROT";
  59     case OP_2SWAP                  : return "OP_2SWAP";
  60     case OP_IFDUP                  : return "OP_IFDUP";
  61     case OP_DEPTH                  : return "OP_DEPTH";
  62     case OP_DROP                   : return "OP_DROP";
  63     case OP_DUP                    : return "OP_DUP";
  64     case OP_NIP                    : return "OP_NIP";
  65     case OP_OVER                   : return "OP_OVER";
  66     case OP_PICK                   : return "OP_PICK";
  67     case OP_ROLL                   : return "OP_ROLL";
  68     case OP_ROT                    : return "OP_ROT";
  69     case OP_SWAP                   : return "OP_SWAP";
  70     case OP_TUCK                   : return "OP_TUCK";
  71
  72     // splice ops
  73     case OP_CAT                    : return "OP_CAT";
  74     case OP_SUBSTR                 : return "OP_SUBSTR";
  75     case OP_LEFT                   : return "OP_LEFT";
  76     case OP_RIGHT                  : return "OP_RIGHT";
  77     case OP_SIZE                   : return "OP_SIZE";
  78
  79     // bit logic
  80     case OP_INVERT                 : return "OP_INVERT";
  81     case OP_AND                    : return "OP_AND";
  82     case OP_OR                     : return "OP_OR";
  83     case OP_XOR                    : return "OP_XOR";
  84     case OP_EQUAL                  : return "OP_EQUAL";
  85     case OP_EQUALVERIFY            : return "OP_EQUALVERIFY";
  86     case OP_RESERVED1              : return "OP_RESERVED1";
  87     case OP_RESERVED2              : return "OP_RESERVED2";
  88
  89     // numeric
  90     case OP_1ADD                   : return "OP_1ADD";
  91     case OP_1SUB                   : return "OP_1SUB";
  92     case OP_2MUL                   : return "OP_2MUL";
  93     case OP_2DIV                   : return "OP_2DIV";
  94     case OP_NEGATE                 : return "OP_NEGATE";
  95     case OP_ABS                    : return "OP_ABS";
  96     case OP_NOT                    : return "OP_NOT";
  97     case OP_0NOTEQUAL              : return "OP_0NOTEQUAL";
  98     case OP_ADD                    : return "OP_ADD";
  99     case OP_SUB                    : return "OP_SUB";
 100     case OP_MUL                    : return "OP_MUL";
 101     case OP_DIV                    : return "OP_DIV";
 102     case OP_MOD                    : return "OP_MOD";
 103     case OP_LSHIFT                 : return "OP_LSHIFT";
 104     case OP_RSHIFT                 : return "OP_RSHIFT";
 105     case OP_BOOLAND                : return "OP_BOOLAND";
 106     case OP_BOOLOR                 : return "OP_BOOLOR";
 107     case OP_NUMEQUAL               : return "OP_NUMEQUAL";
 108     case OP_NUMEQUALVERIFY         : return "OP_NUMEQUALVERIFY";
 109     case OP_NUMNOTEQUAL            : return "OP_NUMNOTEQUAL";
 110     case OP_LESSTHAN               : return "OP_LESSTHAN";
 111     case OP_GREATERTHAN            : return "OP_GREATERTHAN";
 112     case OP_LESSTHANOREQUAL        : return "OP_LESSTHANOREQUAL";
 113     case OP_GREATERTHANOREQUAL     : return "OP_GREATERTHANOREQUAL";
 114     case OP_MIN                    : return "OP_MIN";
 115     case OP_MAX                    : return "OP_MAX";
 116     case OP_WITHIN                 : return "OP_WITHIN";
 117
 118     // crypto
 119     case OP_RIPEMD160              : return "OP_RIPEMD160";
 120     case OP_SHA1                   : return "OP_SHA1";
 121     case OP_SHA256                 : return "OP_SHA256";
 122     case OP_HASH160                : return "OP_HASH160";
 123     case OP_HASH256                : return "OP_HASH256";
 124     case OP_CODESEPARATOR          : return "OP_CODESEPARATOR";
 125     case OP_CHECKSIG               : return "OP_CHECKSIG";
 126     case OP_CHECKSIGVERIFY         : return "OP_CHECKSIGVERIFY";
 127     case OP_CHECKMULTISIG          : return "OP_CHECKMULTISIG";
 128     case OP_CHECKMULTISIGVERIFY    : return "OP_CHECKMULTISIGVERIFY";
 129
 130     // expansion
 131     case OP_NOP1                   : return "OP_NOP1";
 132     case OP_CHECKLOCKTIMEVERIFY    : return "OP_CHECKLOCKTIMEVERIFY";
 133     case OP_CHECKSEQUENCEVERIFY    : return "OP_CHECKSEQUENCEVERIFY";
 134     case OP_NOP4                   : return "OP_NOP4";
 135     case OP_NOP5                   : return "OP_NOP5";
 136     case OP_NOP6                   : return "OP_NOP6";
 137     case OP_NOP7                   : return "OP_NOP7";
 138     case OP_NOP8                   : return "OP_NOP8";
 139     case OP_NOP9                   : return "OP_NOP9";
 140     case OP_NOP10                  : return "OP_NOP10";
 141
 142     case OP_INVALIDOPCODE          : return "OP_INVALIDOPCODE";
 143
 144     // Note:
 145     //  The template matching params OP_SMALLINTEGER/etc are defined in opcodetype enum
 146     //  as kind of implementation hack, they are *NOT* real opcodes.  If found in real
 147     //  Script, just let the default: case deal with them.
 148
 149     default:
 150         return "OP_UNKNOWN";
 151     }
 152 }
 153
 154 unsigned int CScript::GetSigOpCount(bool fAccurate) const
 155 {
 156     unsigned int n = 0;
 157     const_iterator pc = begin();
 158     opcodetype lastOpcode = OP_INVALIDOPCODE;
 159     while (pc < end())
 160     {
 161         opcodetype opcode;
 162         if (!GetOp(pc, opcode))
 163             break;
 164         if (opcode == OP_CHECKSIG || opcode == OP_CHECKSIGVERIFY)
 165             n++;
 166         else if (opcode == OP_CHECKMULTISIG || opcode == OP_CHECKMULTISIGVERIFY)
 167         {
 168             if (fAccurate && lastOpcode >= OP_1 && lastOpcode <= OP_16)
 169                 n += DecodeOP_N(lastOpcode);
 170             else
 171                 n += MAX_PUBKEYS_PER_MULTISIG;
 172         }
 173         lastOpcode = opcode;
 174     }
 175     return n;
 176 }
 177
 178 unsigned int CScript::GetSigOpCount(const CScript& scriptSig) const
 179 {
 180     if (!IsPayToScriptHash())
 181         return GetSigOpCount(true);
 182
 183     // This is a pay-to-script-hash scriptPubKey;
 184     // get the last item that the scriptSig
 185     // pushes onto the stack:
 186     const_iterator pc = scriptSig.begin();
 187     std::vector<unsigned char> vData;
 188     while (pc < scriptSig.end())
 189     {
 190         opcodetype opcode;
 191         if (!scriptSig.GetOp(pc, opcode, vData))
 192             return 0;
 193         if (opcode > OP_16)
 194             return 0;
 195     }
 196
 197     /// ... and return its opcount:
 198     CScript subscript(vData.begin(), vData.end());
 199     return subscript.GetSigOpCount(true);
 200 }
 201
 202 bool CScript::IsPayToScriptHash() const
 203 {
 204     // Extra-fast test for pay-to-script-hash CScripts:
 205     return (this->size() == 23 &&
 206             (*this)[0] == OP_HASH160 &&
 207             (*this)[1] == 0x14 &&
 208             (*this)[22] == OP_EQUAL);
 209 }
 210
 211 bool CScript::IsPayToWitnessScriptHash() const
 212 {
 213     // Extra-fast test for pay-to-witness-script-hash CScripts:
 214     return (this->size() == 34 &&
 215             (*this)[0] == OP_0 &&
 216             (*this)[1] == 0x20);
 217 }
 218
 219 // A witness program is any valid CScript that consists of a 1-byte push opcode
 220 // followed by a data push between 2 and 40 bytes.
 221 bool CScript::IsWitnessProgram(int& version, std::vector<unsigned char>& program) const
 222 {
 223     if (this->size() < 4 || this->size() > 42) {
 224         return false;
 225     }
 226     if ((*this)[0] != OP_0 && ((*this)[0] < OP_1 || (*this)[0] > OP_16)) {
 227         return false;
 228     }
 229     if ((size_t)((*this)[1] + 2) == this->size()) {
 230         version = DecodeOP_N((opcodetype)(*this)[0]);
 231         program = std::vector<unsigned char>(this->begin() + 2, this->end());
 232         return true;
 233     }
 234     return false;
 235 }
 236
 237 bool CScript::IsPushOnly(const_iterator pc) const
 238 {
 239     while (pc < end())
 240     {
 241         opcodetype opcode;
 242         if (!GetOp(pc, opcode))
 243             return false;
 244         // Note that IsPushOnly() *does* consider OP_RESERVED to be a
 245         // push-type opcode, however execution of OP_RESERVED fails, so
 246         // it's not relevant to P2SH/BIP62 as the scriptSig would fail prior to
 247         // the P2SH special validation code being executed.
 248         if (opcode > OP_16)
 249             return false;
 250     }
 251     return true;
 252 }
 253
 254 bool CScript::IsPushOnly() const
 255 {
 256     return this->IsPushOnly(begin());
 257 }
 258
 259 std::string CScriptWitness::ToString() const
 260 {
 261     std::string ret = "CScriptWitness(";
 262     for (unsigned int i = 0; i < stack.size(); i++) {
 263         if (i) {
 264             ret += ", ";
 265         }
 266         ret += HexStr(stack[i]);
 267     }
 268     return ret + ")";
 269 }
 270
 271 bool CScript::HasValidOps() const
 272 {
 273     CScript::const_iterator it = begin();
 274     while (it < end()) {
 275         opcodetype opcode;
 276         std::vector<unsigned char> item;
 277         if (!GetOp(it, opcode, item) || opcode > MAX_OPCODE || item.size() > MAX_SCRIPT_ELEMENT_SIZE) {
 278             return false;
 279         }
 280     }
 281     return true;
 282 }